In conventional art, when a base station, which serves a user equipment (UE), is not suitable for servicing it, the UE will be handed over to another base station. In the prior art, the process is achieved by a following manner.
A source base station (for example, an evolved NodeB (eNB)) sends a handover request message to a target eNB.
If the handover is accepted, the target eNB points out, in a handover request acknowledge (Handover Request ACK) message, a tunnel endpoint General Packet Radio Service (GPRS) tunneling protocol (GPRS Tunneling Protocol, GTP for short) where forwarding data is expected to be received. The GTP tunnel endpoint includes a transport layer address and a GTP Tunnel Endpoint Identifier (Tunnel Endpoint ID, or TEID).
After receiving the Handover Request ACK message, a source eNB indicates that the UE hands over from the source eNB to the target eNB.
The inventor found that, in the conventional art, a handover flow can merely hand over a UE from one cell to another cell, and a handover could not performed when there exists more than one source cell or target cell.